Limit Sn
1. **State the problem:** We want to find the limit as $n \to \infty$ of the sequence
$$S_n = \sin \left( \frac{(n+1) \pi}{12n+11} \right).$$
2. **Analyze the argument inside the sine:**
Consider the argument of the sine function:
$$\theta_n = \frac{(n+1) \pi}{12n+11}.$$
3. **Simplify the fraction inside the argument:**
Divide numerator and denominator by $n$:
$$\theta_n = \frac{(n+1) \pi}{12n+11} = \frac{\pi \left(1 + \frac{1}{n}\right)}{12 + \frac{11}{n}}.$$
4. **Take the limit of the argument as $n \to \infty$:**
As $n \to \infty$, $\frac{1}{n} \to 0$, so
$$\lim_{n \to \infty} \theta_n = \frac{\pi (1 + 0)}{12 + 0} = \frac{\pi}{12}.$$
5. **Use continuity of sine to find the limit of $S_n$:**
Since sine is continuous,
$$\lim_{n \to \infty} S_n = \sin \left( \lim_{n \to \infty} \theta_n \right) = \sin \left( \frac{\pi}{12} \right).$$
6. **Evaluate $\sin(\pi/12)$:**
Recall that $\pi/12 = 15^\circ$, and
$$\sin \frac{\pi}{12} = \sin 15^\circ = \frac{\sqrt{6} - \sqrt{2}}{4} \approx 0.2588.$$
**Final answer:**
$$\boxed{0.259}$$ (rounded to three decimal places)